24小时热门版块排行榜    

查看: 778  |  回复: 4

doeboy

金虫 (小有名气)

[求助] 求高人指点一个常微分方程问题

如图

这个方程的解是什么?是数学物理里面的某个特殊函数吗?万分感谢!!
回复此楼

» 猜你喜欢

» 本主题相关价值贴推荐,对您同样有帮助:

已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

dbb627

荣誉版主 (著名写手)

【答案】应助回帖


感谢参与,应助指数 +1
doeboy: 金币+1, 有帮助 2012-04-18 10:37:28
y是x的函数,还是t的函数
>> y=dsolve('D2y=x^2*y','x')

y =

(C6*besselk(1/4, x^2/2)*(x^2)^(1/2))/(pi^(1/2)*x^(1/2)) + (pi*2^(1/2)*4^(1/4)*C5*besseli(1/4, x^2/2)*(x^2)^(1/2))/(4*x^(1/2)*gamma(3/4))

>> y=dsolve('D2y=x^2*y','t')

y =

C2/exp(t*x) + C3*exp(t*x)
The more you learn, the more you know, the more you know, and the more you forget. The more you forget, the less you know. So why bother to learn.
2楼2012-04-18 10:32:36
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

doeboy

金虫 (小有名气)

引用回帖:
2楼: Originally posted by dbb627 at 2012-04-18 10:32:36:
y是x的函数,还是t的函数
>> y=dsolve('D2y=x^2*y','x')

y =

(C6*besselk(1/4, x^2/2)*(x^2)^(1/2))/(pi^(1/2)*x^(1/2)) + (pi*2^(1/2)*4^(1/4)*C5*besseli(1/4, x^2/2)*(x^2)^(1/2))/(4*x^(1/2)* ...

y是x的函数
3楼2012-04-18 10:36:54
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

dbb627

荣誉版主 (著名写手)

【答案】应助回帖

★ ★ ★ ★ ★ ★ ★ ★ ★
doeboy: 金币+9, ★★★★★最佳答案 2012-04-18 10:44:02
引用回帖:
3楼: Originally posted by doeboy at 2012-04-18 10:36:54:
y是x的函数

数学物理里应该解出贝塞尔函数
matlab解的
y=dsolve('D2y=x^2*y','x')

y =

(C6*besselk(1/4, x^2/2)*(x^2)^(1/2))/(pi^(1/2)*x^(1/2)) + (pi*2^(1/2)*4^(1/4)*C5*besseli(1/4, x^2/2)*(x^2)^(1/2))/(4*x^(1/2)*gamma(3/4))
The more you learn, the more you know, the more you know, and the more you forget. The more you forget, the less you know. So why bother to learn.
4楼2012-04-18 10:38:35
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

doeboy

金虫 (小有名气)

引用回帖:
4楼: Originally posted by dbb627 at 2012-04-18 10:38:35:
数学物理里应该解出贝塞尔函数
matlab解的
y=dsolve('D2y=x^2*y','x')

y =

(C6*besselk(1/4, x^2/2)*(x^2)^(1/2))/(pi^(1/2)*x^(1/2)) + (pi*2^(1/2)*4^(1/4)*C5*besseli(1/4, x^2/2)*(x^2)^(1/2))/(4*x ...

恩,已经找到了,是Parabolic cylinder function,参见http://en.wikipedia.org/wiki/Parabolic_cylinder_function,多谢帮助!
5楼2012-04-18 10:43:56
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
相关版块跳转 我要订阅楼主 doeboy 的主题更新
最具人气热帖推荐 [查看全部] 作者 回/看 最后发表
[考研] 272求调剂 +4 田智友 2026-02-28 4/200 2026-03-01 06:43 by 刘兵
[考研] 285求调剂 +6 满头大汗的学生 2026-02-28 6/300 2026-03-01 06:29 by Trying]
[基金申请] 面上模板改不了页边距吧? +5 ieewxg 2026-02-25 6/300 2026-03-01 00:10 by addressing
[考研] 307求调剂 +4 73372112 2026-02-28 6/300 2026-03-01 00:04 by ll247
[考研] 304求调剂 +3 52hz~~ 2026-02-28 5/250 2026-03-01 00:00 by 52hz~~
[考研] 272求调剂 +3 材紫有化 2026-02-28 3/150 2026-02-28 22:52 by ms629
[考研] 292求调剂 +3 yhk_819 2026-02-28 3/150 2026-02-28 21:57 by gaoxiaoniuma
[考研] 290求调剂 +5 材料专硕调剂; 2026-02-28 6/300 2026-02-28 21:40 by gaoxiaoniuma
[考研] 295求调剂 +5 19171856320 2026-02-28 5/250 2026-02-28 21:39 by gaoxiaoniuma
[考博] 26申博 +4 想申博! 2026-02-26 4/200 2026-02-28 21:37 by limorning
[考研] 材料学调剂 +5 提神豆沙包 2026-02-28 5/250 2026-02-28 21:34 by gaoxiaoniuma
[考研] 材料类求调剂 +6 wana_kiko 2026-02-28 6/300 2026-02-28 21:20 by gaoxiaoniuma
[考研] 求调剂 +4 repeatt?t 2026-02-28 4/200 2026-02-28 21:16 by gaoxiaoniuma
[考研] 高分子化学与物理调剂 +4 好好好1233 2026-02-28 7/350 2026-02-28 20:42 by 好好好1233
[考研] 085600材料工程一志愿中科大总分312求调剂 +8 吃宵夜1 2026-02-28 10/500 2026-02-28 20:27 by L135790
[考研] 276求调剂 +3 路lyh123 2026-02-28 4/200 2026-02-28 19:45 by 路lyh123
[高分子] 求环氧树脂研发1名 +3 孙xc 2026-02-25 11/550 2026-02-28 16:57 by ichall
[考研] 0856调剂 +3 刘梦微 2026-02-28 3/150 2026-02-28 13:22 by houyaoxu
[基金申请] 面上可以超过30页吧? +12 阿拉贡aragon 2026-02-22 13/650 2026-02-26 22:09 by Hahaxia
[硕博家园] 【博士招生】太原理工大学2026化工博士 +4 N1ce_try 2026-02-24 8/400 2026-02-26 08:40 by N1ce_try
信息提示
请填处理意见